A polyaromatic hydrocarbon is a compound that includes a plurality of aromatic materials such as benzene rings, etc., and is utilized as a precursor in the course of producing carbon fibers, which are used as a structural material reinforcing agent.
Conventionally, the polyaromatic hydrocarbon may be oxidized by oxidizing pitch, obtained from fossil fuel or fossil fuel products, using concentrated nitric acid (HNO3), sulfuric acid (H2SO4) or a mixture thereof.
However, the preparation of polyaromatic oxide by the above conventional method is problematic because a strong acid such as nitric acid or sulfuric acid is used, which is dangerous, and also because nitrogen oxide such as NOx is produced in the course of reaction and purification, and thus related devices are required to be resistant to corrosion, undesirably increasing production costs, and furthermore, a large amount of industrial wastewater may be generated, further increasing processing costs.
For example, Japanese Patent Application Publication NO. 2008-248412 discloses a dispersant for carbon fibers, but does not describe any improvement to the conventional method of producing polyaromatic oxide.
There is a demand for a method of easily preparing polyaromatic oxide without the use of an oxidant, i.e. a strong acid.